A microfiche, as the term is used in the art, constitutes an exposed film approximately the size of a conventional indexing card containing rows and columns of separate frames or images. Each frame or image, for example, might represent the reduction of a printed page of material from a document and in the event that five rows and twelve columns are provided there can be recorded on a single microfiche sixty pages of such information. The purpose for microfiche is similar to that of microfilm. However, microfiche has one advantage over microfilm in that a selected portion of a recorded document can readily be searched and reviewed without having to reel through an entire continuous microfilm. Special viewers are provided for microfiche wherein the microfiche itself is inserted in the viewer and positioned along rectangular coordinates to cause the desired frame or image on the microfiche to be projected onto the viewer screen.
Normally, a master file of microfiche containing reduced data of an entire operation is maintained. If specific data is required from this file, the particular microfiche containing this data is pulled and may be read in a viewer as described above. On the other hand, personnel at physically spaced locations may wish to examine the records and towards this end it is common practice to simply make a duplicate of the master microfiche and send this on to those interested persons, the original master microfiche being restored in the master file. In fact, it is not uncommon practice to provide a large number of duplicates of a single microfiche in order that several different persons can review data at the same time.
In view of the foregoing, several different types of microfiche duplicators have been developed. These duplicators normally include a platen for receiving a master microfiche, a duplicate of which is to be made. The master microfiche is moved into a housing wherein it is positioned in contact with duplicate microfiche film and a contact print is made. In the more sophisticated versions, the contact print is then automatically developed by an appropriate development chamber within the housing of the apparatus and the duplicate copy can be retrieved from an appropriate tray or hopper.
While such duplicators as described above serve their function well, there is room for considerable improvement. The use of microfiche in the industry has proliferated to an enormous extent and literally thousands of copies of masters may be required in each of many commercial operations. The basic problem to be overcome is that of providing a microfiche duplicating apparatus which minimizes requirements on the operator in making duplicates to the end that greater speed can be achieved and yet assure that the duplicate microfiche are of acceptable quality.
To increase the speed of copy production, it has already been proposed to provide a double platen arrangement such that an operator can load one platen with a master microfiche and position the same within the apparatus housing for contact printing with duplicate film within the housing and while this process is being carried out, a second master microfiche can be loaded on the second platen. This second platen is then positioned in the housing and the master microfiche in the first platen removed and a third master placed therein.
Notwithstanding the provision of a double platen to increase the speed of reproduction, there are still severe demands on the operator. First, it is vital that the master microfiche be exactly positioned on the receiving platen and towards this end hold-down clips and the like have been provided but there is still a certain amount of time involved in the securing of the master microfiche on the platen. Secondly, where a reel of duplicate film is contained in the housing, it is necessary to assure that an exact length of microfiche film from this duplicate reel is properly positioned for registration with the master microfiche when the same is moved into the housing for the contact printing. As the reel of duplicate microfiche film in the housing becomes depleted, the pulling forces on the film wound on the reel vary and thus proper registration of the duplicate film with the master microfiche cannot always be assured. Thirdly, in order to provide intermittent movement of the duplicate reel of film in the housing, stepper motors have been used in an effort to assure that equal successive lengths of film will be properly positioned for contact printing with the master microfiche. However, stepper motors are not always accurate and if the motor is off by a single step, poor registration between the master microfiche and given length of duplicate film results. Thus, there can occur overlaps when making a number of successive copies. Fourthly, with present-day machines there is normally provided manually operable push-buttons or the like for actuating the apparatus in the making of each duplicate copy and as a result, an operator must use one hand to operate these controls leaving only one hand free for a part of the time at least necessary in positioning successive master microfiche on the platens.